MIR137 polygenic risk for schizophrenia and ephrin-regulated pathway: Role in lateral ventricles and corpus callosum volume

Background/Objective. Enlarged lateral ventricle (LV) volume and decreased volume in the corpus callosum (CC) are hallmarks of schizophrenia (SZ). We previously showed an inverse correlation between LV and CC volumes in SZ, with global functioning decreasing with increased LV volume. This study investigates the relationship between LV volume, CC abnormalities, and the microRNA MIR137 and its regulated genes in SZ, because of MIR137's essential role in neurodevelopment. Methods. Participants were 1224 SZ probands and 1466 unaffected controls from the GENUS Consortium. Brain MRI scans, genotype, and clinical data were harmonized across cohorts and employed in the analyses. Results. Increased LV volumes and decreased CC central, mid-anterior, and mid-posterior volumes were observed in SZ probands. The MIR137-regulated ephrin pathway was significantly associated with CC:LV ratio, explaining a significant proportion (3.42 %) of CC:LV variance, and more than for LV and CC separately. Other pathways explained variance in either CC or LV, but not both. CC:LV ratio was also positively correlated with Global Assessment of Functioning, supporting previous subsample findings. SNP-based heritability estimates were higher for CC central:LV ratio (0.79) compared to CC or LV separately. Discussion. Our results indicate that the CC:LV ratio is highly heritable, influenced in part by variation in the MIR137-regulated ephrin pathway. Findings suggest that the CC:LV ratio may be a risk indicator in SZ that correlates with global functioning.

'I am proud of how I handled it'. Exploring the impact of the COVID-19 pandemic and related restrictions on well-being of adults with severe mental illness using qualitative methods

BACKGROUND

The coronavirus disease 2019 (COVID-19) pandemic and related restrictions globally impacted mental health, particularly for those with pre-existing severe mental illness (SMI). This qualitative study examined how adults with SMI perceived the effects of the COVID-19 pandemic and related restrictions in the Netherlands, focusing on their personal recovery, well-being and daily life, including an exploration of factors influencing these effects.

METHODS

Semi-structured interviews were conducted, audio-recorded and transcribed verbatim. Reflexive thematic analysis was applied. Purposive sampling was used to ensure diversity of individuals with SMI (i.e., age, gender, diagnosis, cultural background and mental healthcare institution).

RESULTS

Twenty participants (median age: 45 years [SD: 12, 8]; 11 females) were interviewed between May and July 2023. Findings revealed a wide range of experiences: while some individuals reported a negative impact on their existing psychiatric symptoms, others described adaptability, resilience and even positive effects of COVID-19 restrictions on their mental health and well-being. Factors influencing the heterogeneic perceptions of the COVID-19 pandemic and related restrictions include the availability of trusted social relationships and enduring interactions with health professionals.

CONCLUSION

Personalised support, both socially and professionally, is crucial for addressing fears, building resilience, reducing isolation and encouraging positive coping strategies for individuals with SMI during external crises. In this project, a participatory research approach that integrated the lived experience perspective helped uncover the unique perceptions of people with SMI with regard to the pandemic and related restrictions.

PATIENT OR PUBLIC CONTRIBUTION

The study used a participatory action research approach, with experts-by-experience involved in every stage of the project as part of the research team. This included engagement with the funding application process, recruitment strategies for interviews, developing the interview guide, piloting the interview, interpreting findings, and knowledge dissemination activities.

[Lifestyle in young adults with and without a psychotic disorder]

Background Patients with psychotic disorders have a higher risk of physical illnesses on account of genetic predisposition, poorer access to healthcare, medication use, environmental factors and lifestyle. Because healthy lifestyle behaviour is established at young age, it is important to signal problems in good time. A lifestyle screening might be useful in this respect. Aim To describe the lifestyle characteristics of patients in a mental health clinic for young adults (age: 18-28 years) with early psychotic disorder based on parts of the instrument ‘Lifestyle-in-the-picture’ compared to healthy controls. We also discuss experiences of lifestyle coaches in applying ‘Lifestyle-in-the-picture’. Method Lifestyle characteristics and lifestyle behaviour of 90 patients with a psychotic disorder and 137 young adults from the general population were compared quantitatively. Additionally, interviews were held with lifestyle coaches as to the use of the instrument ‘Lifestyle-in-the-picture’. Results The young adult patients had considerably poorer results on lifestyle aspects than controls: increased body mass index (BMI 53% versus 18%), smoking, addiction and unhealthy eating and activity patterns. They were more dissatisfied with their physical and mental health. According to the lifestyle coaches, the ‘Lifestyle-in-the-picture’ instrument was a good starting point to work on improvement with patients since the instrument provided insight in the healthy and unhealthy aspects of their lifestyle and gave directions to set goals. Conclusions Young adults with a psychotic disorder have an unhealthy lifestyle and also more risk factors compared to controls. Lifestyle screening programmes are important to discuss health risks in time and which steps for improvement can be taken. The step from insight to actual more healthy behaviour is challenging.

fMRI connectivity as a biomarker of antipsychotic treatment response: A systematic review

BACKGROUND

Antipsychotic drugs are the first-choice therapy for psychotic episodes, but antipsychotic treatment response (AP-R) is unpredictable and only becomes clear after weeks of therapy. A biomarker for AP-R is currently unavailable. We reviewed the evidence for the hypothesis that functional magnetic resonance imaging functional connectivity (fMRI-FC) is a predictor of AP-R or could serve as a biomarker for AP-R in psychosis.

METHOD

A systematic review of longitudinal fMRI studies examining the predictive performance and relationship between FC and AP-R was performed following PRISMA guidelines. Technical and clinical aspects were critically assessed for the retrieved studies. We addressed three questions: Q1) is baseline fMRI-FC related to subsequent AP-R; Q2) is AP-R related to a change in fMRI-FC; and Q3) can baseline fMRI-FC predict subsequent AP-R?

RESULTS

In total, 28 articles were included. Most studies were of good quality. fMRI-FC analysis pipelines included seed-based-, independent component- / canonical correlation analysis, network-based statistics, and graph-theoretical approaches. We found high heterogeneity in methodological approaches and results. For Q1 (N = 17) and Q2 (N = 18), the most consistent evidence was found for FC between the striatum and ventral attention network as a potential biomarker of AP-R. For Q3 (N = 9) accuracy's varied form 50 till 93%, and prediction models were based on FC between various brain regions.

CONCLUSION

The current fMRI-FC literature on AP-R is hampered by heterogeneity of methodological approaches. Methodological uniformity and further improvement of the reliability and validity of fMRI connectivity analysis is needed before fMRI-FC analysis can have a place in clinical applications of antipsychotic treatment.

Effectiveness and implementation of a MUltidisciplinary Lifestyle focused approach in the Treatment of Inpatients with mental illness (MULTI+): a stepped wedge study protocol

Introduction

People with mental illness (MI) have a reduced life expectancy compared to the general population, mostly attributable to somatic diseases caused by poor physical health. Modifiable lifestyle factors are increasingly associated with the onset of somatic diseases in people with MI. Despite the increasing evidence for the efficacy of lifestyle interventions there is little change in routine clinical care. This discrepancy is referred to as the implementation gap and has caused a need for effectiveness and implementation research in real-world settings.

Objectives

This study investigates the health outcomes and implementation of a multidisciplinary lifestyle focused approach in treatment of inpatients with mental illness (MULTI+).

Methods

This is an open cohort stepped wedge cluster randomized trial in inpatients psychiatric wards of GGz Centraal. Three clusters are randomly allocated to one of the three pre-defined steps to integrate MULTI+. MULTI+ can be tailored to fit individual psychiatric wards and includes 10 core components aimed at improving lifestyle factors. The primary outcome is to investigate whether there is a greater decrease in the QRISK3 cardiovascular risk score after receiving MULTI+ as compared to treatment as usual. Secondary outcomes include somatic and mental health outcomes, lifestyle factors, and implementation factors.

Results

First results expected in 2022.

Conclusions

To our knowledge, this will be the first large-scale study evaluating the long-term effects of a multidisciplinary, multicomponent approach aimed at improving lifestyle factors. We expect that this approach will increase long-term sustainability and can serve as a potential blueprint for future implementation of lifestyle interventions to improve routine clinical care.

Disclosure

No significant relationships.

Cardiorespiratory fitness and self-reported physical activity levels of referring mental healthcare professionals, and their attitudes and referral practices related to exercise and somatic care

Introduction

Physical activity (PA) interventions can improve mental and physical health in people with mental illness, especially when delivered by qualified exercise professionals. Also, the behaviour, engagement and support of referring mental healthcare professionals (HCP) seems essential, but research is scarce.

Objectives

Studying the physical fitness and PA of HCP and the relationship with their attitudes and referral practices related to PA interventions

Methods

HCP at the Dutch Association for Psychiatry conference (2019) were invited to an online questionnaire (demographic/work characteristics, stress, PA levels, knowledge/attitudes regarding PA and referral practices) and cycle ergometer test. Linear and logistic regression were used to study the strongest associations.

Results

115 HCP completed the questionnaire. 40 also completed the ergometer test. 43% (n=50) met the national PA guidelines (≥150min moderate-to-vigorous PA and ≥2x bone/muscle-strengthening exercises a week). Women, HCP in training and HCP with more stress were less active and less likely to meet PA guidelines. HCP with personal experience with an exercise professional were more active and met guidelines more often. Knowledge/attitudes on physical health and PA were positive. Patients were more often referred to PA interventions by HCP who met PA guidelines (OR=2.56, 95%BI=0.85–7.13) or had higher beliefs that exercise professionals can increase adherence to PA interventions (OR=3.72, 95%BI=1.52–9.14).

Conclusions

It’s positive that HCP report importance and relevance of PA in mental healthcare. Although there is strong evidence for PA interventions in the treatment of people with mental illness, referral to such interventions can partly depend on the PA behaviour and attitude of patients’ physician/clinician.

Disclosure

No significant relationships.

The association between lifestyle factors, and physical and mental health in inpatients with MI: a network analysis

Introduction

People with mental illness (MI) have a reduced life expectancy compared to the general population, mostly attributable to somatic diseases caused by poor physical health. Lifestyle factors (exercise, sleep, diet, substance use) are associated with poor physical and mental health. Although lifestyle factors, and physical and mental health are believed to be interconnected, research has mainly focused on one-sided relationships. Currently, we are implementing a lifestyle focussed approach in treatment, in which we assess lifestyle factors as well as physical and mental health of people with MI on a large scale (˜850 places of residence).

Objectives

To investigate the association between lifestyle factors, and physical and mental health in people with MI.

Methods

Baseline data from an open cohort cluster randomized stepped wedge study. Lifestyle factors (exercise, sleep, diet, substance use), physical health, medication use and psychological health (symptoms, quality of life) were assessed using data from patient files and questionnaires. Associations will be analysed with network analyses.

Results

First results (N≈1600) show that 54% of patients have high blood pressure, 51% have excessive waist circumference, 46% are experiencing sleep problems, 71% smoke and 88% do not meet exercise guidelines. Patients experience a lower quality of life compared to the general population.

Conclusions

Initial results show that patients have poor physical health, low quality of life and an unhealthy lifestyle. Further analyses are currently being conducted to gain insight in the complex pattern between lifestyle factors, and physical and mental health. This can contribute to the improvement of routine clinical care.

Disclosure

No significant relationships.

Effectiveness and implementation of a multidisciplinary lifestyle focused approach in the treatment of inpatients with mental illness (MULTI +): a stepped wedge study protocol

BACKGROUND

People with mental illness have a reduced life expectancy compared to the general population. Despite the increasing evidence for the efficacy of lifestyle interventions there is little change in routine clinical care. This discrepancy is often referred to as the implementation gap and has caused a need for effectiveness and implementation research in real-world settings. Our study assesses the effectiveness and implementation of a multidisciplinary lifestyle focused approach in the treatment of inpatients with mental illness (MULTI +).

METHODS

An open cohort stepped wedge cluster randomized trial in inpatients psychiatric wards of GGz Centraal, the Netherlands. The wards are divided into three clusters based on geographical region. These clusters are randomly allocated to one of the three pre-defined steps to integrate MULTI + . MULTI + can be tailored to fit individual psychiatric wards and includes 10 core components aimed at improving lifestyle factors. The primary outcome is to investigate the difference in the mean QRISK3 score of patients receiving MULTI + compared to patients receiving TAU. Secondary outcomes include somatic and mental health outcomes, lifestyle factors, and implementation factors. Findings will be analysed using mixed model analyses.

DISCUSSION

The MULTI + study is the first large-scale study evaluating the long-term effects of a multidisciplinary, multicomponent approach aimed at improving lifestyle factors in routine inpatient mental health care. A limitation of this study is the risk of missing data due to the large-scale, real-world setting of this study. Furthermore, implementation monitoring and external events that may influence outcomes could be difficult to account for. Strengths of this study are the focus on effectiveness as well as implementation and the inclusion of both patient and health care professionals' perspectives. Effectiveness studies in routine clinical care can advance our knowledge on lifestyle interventions in real-world settings.

TRIAL REGISTRATION

ClinicalTrials.gov registration. Identifier: NCT04922749 . Retrospectively registered 3th of June 2021.

[Psychiatric symptoms and COVID-19: results of a national case register]

BACKGROUND

Psychiatric disorders are associated with a more severe course of COVID-19. COVID-19 can also lead to psychiatric symptoms.

AIM

To gain insight into vulnerabilities and protective factors for the course of COVID-19 in a Dutch (neuro)psychiatric population.

METHOD

Patients were divided into three groups: patients with pre-existent mental disorders without and with new (neuro)psychiatric symptoms (NPS) during COVID-19 and patients without pre-existent mental disorders who developed de novo NPS during COVID-19. We summarize the characteristics of each group and compare the subgroups with inferential statistics.

RESULTS

186 patients were included in the case register. Patients with NPS showed a more severe course of COVID-19. Mortality in patients with NPS was higher in patients with pre-existent mental disorders compared to patients without pre-existent mental disorders. The most frequently reported de novo psychiatric symptoms during COVID-19 were delirium (46-70%), anxiety (53-54%) and insomnia (18-42%).

CONCLUSION

NPS might be an expression of a more severe COVID-19 episode. In patients who developed NPS during COVID-19 we found evidence for a higher mortality risk in patients with pre-existent mental disorders. Extra vigilance for neuropsychiatric symptoms during COVID-19 is warranted.

[Tapering of psychotropic drugs: current practice and needs of patients and their relatives]

BACKGROUND

The prevalence of mental illness has remained stable in recent decades, yet the use of psychotropic drugs has increased. This trend suggests that psychotropic drugs are being prescribed with an unnecessary frequency. Internationally, there is growing attention for deprescribing.

AIM

To investigate what experiences and needs patients and their loved ones/relatives have with regard to deprescribing of psychotropics.

METHOD

An online questionnaire was distributed among members of the MIND mental health care panel, which consists of (former) patients with a psychiatric disorder and their loved ones.

RESULTS

A total of 564 respondents took part in this survey. Most patients have phased out/stopped their psychotropic drugs (83.8%). This was usually done at the initiative of the patient (66.7%), in consultation with the practitioner (72.9%). The practitioner only took the initiative to deprescribe in 15.1% of the cases. In 68.6% tapering was not discussed at the start of psychotropic drug use. Patients did not experience willingness from practitioners in deprescribing, and would like to discuss deprescribing more often (79.5%).

CONCLUSION

There is an undeniable demand among patients and near ones for more emphasis on deprescribing of psychotropic drugs. We advise to include this topic in the shared decision making process.

Schizophrenia as a progressive brain disease

There is convincing evidence that schizophrenia is characterized by abnormalities in brain volume. At the Department of Psychiatry of the University Medical Centre Utrecht, Netherlands, we have been carrying out neuroimaging studies in schizophrenia since 1995. We focused our research on three main questions. First, are brain volume abnormalities static or progressive in nature? Secondly, can brain volume abnormalities in schizophrenia be explained (in part) by genetic influences? Finally, what environmental factors are associated with the brain volume abnormalities in schizophrenia?

Based on our findings we suggest that schizophrenia is a progressive brain disease. We showed different age-related trajectories of brain tissue loss suggesting that brain maturation that occurs in the third and fourth decade of life is abnormal in schizophrenia. Moreover, brain volume has been shown to be a useful phenotype for studying schizophrenia. Brain volume is highly heritable and twin and family studies show that unaffected relatives show abnormalities that are similar, but usually present to a lesser extent, to those found in the patients. However, also environmental factors play a role. Medication intake is indeed a confounding factor when interpreting brain volume (change) abnormalities, while independent of antipsychotic medication intake brain volume abnormalities appear influenced by the outcome of the illness.

In conclusion, schizophrenia can be considered as a progressive brain disease with brain volume abnormalities that are for a large part influenced by genetic factors. Whether the progressive volume change is also mediated by genes awaits the results of longitudinal twin analyses. One of the main challenges for the coming years, however, will be the search for gene-by-environment interactions on the progressive brain changes in schizophrenia.

[Not Available]

Course of covid-19 infections and impact on mental health; setting up a national case register.

[Evidence based eHealth applications targeting improvement of lifestyle habits of people with severe mental illness]

People with severe mental illness (smi) often suffer from long lasting psychiatric symptoms, have a lower quality of life and a worse physical condition compared to the general population. Healthy lifestyle habits improve mental and physical health. EHealth (digital applications in healthcare) could play a role in the improvement of lifestyle habits in this population.<br/> AIM: To provide an overview of evidence based eHealth applications targeting improvement of lifestyle habits of people with smi.<br/> METHOD: We performed a narrative rapid review.<br/> RESULTS: There are many eHealth applications targeting improvement of lifestyle habits, but few are specifically targeting the psychiatric population and evidence based. Most studies concerned small pilot studies.<br/> CONCLUSION: EHealth applications might be used as a support in the guidance and treatment of unhealthy lifestyle habits in people with smi, however more research is needed.

[Integral care necessary for patients with complex somatic, psychic and social problems]

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[Regional healthcare labels: differences in care needs and psychosocial functioning]

Severe mental illnesses (SMI) are associated with high mental healthcare and other healthcare costs. In 2012, mental healthcare labels were developed to create more transparency between insurance companies, municipalities, and mental healthcare. The labels are based on care intensity, and should provide a regional overview of the present groups of patients with SMI.<br/> AIM: Explore the functionality and validity of the used labels in relation to needs for care and psychosocial functioning.<br/> METHOD: The ROM data (needs for care, functioning) from 706 patients were tested per label by Chi-square tests and ANOVAs. For two high complex labels (alarming care avoiders and persons with safety risks), repeated measures ANOVAs and McNemar tests were used to analyse changes in functioning and needs over time.<br/> RESULTS: To a limited extent, the labels were distinctive in care needs and functioning. The most restrictions in functioning and (unfulfilled) needs were present in the labels 'alarming care avoiders' and 'avoiding danger'. These findings were stable over time.<br/> CONCLUSION: The labels are not sufficiently distinctive. To enhance regional care planning, it is desirable to combine existing information on healthcare labels with information on care needs and functioning. KEY WORDS functioning, mental healthcare labels, needs for care, routine outcome monitoring, severe mental illness.

Reward-related brain structures are smaller in patients with schizophrenia and comorbid metabolic syndrome

OBJECTIVE

Metabolic syndrome (MS) is highly prevalent in schizophrenia and often a consequence of unhealthy behaviour. Reward-related brain areas might be associated with MS, since they play a major role in regulating health behaviour. This study examined the relationship between MS and brain volumes related to the reward system in schizophrenia.

METHOD

We included patients with schizophrenia, with MS (MS+; n = 23), patients with schizophrenia, without MS (MS-; n = 48), and healthy controls (n = 54). Global brain volumes and volumes of (sub)cortical areas, part of the reward circuit, were compared between patients and controls. In case of a significant brain volume difference between patients and controls, the impact of MS in schizophrenia was examined.

RESULTS

Patients had smaller total brain (TB; P = 0.001), GM (P = 0.010), larger ventricles (P = 0.026), and smaller reward circuit volume (P < 0.001) than controls. MS+ had smaller TB (P = 0.017), GM (P = 0.008), larger ventricles (P = 0.015), and smaller reward circuit volume (P = 0.002) than MS-. MS+ had smaller orbitofrontal cortex (OFC; P = 0.002) and insula volumes (P = 0.005) and smaller OFC (P = 0.008) and insula cortical surface area (P = 0.025) compared to MS-.

CONCLUSION

In schizophrenia, structural brain volume reductions in areas of the reward circuitry appear to be related to comorbid MS.

Associations between psychosis endophenotypes across brain functional, structural, and cognitive domains

BACKGROUND

A range of endophenotypes characterise psychosis, however there has been limited work understanding if and how they are inter-related.

METHODS

This multi-centre study includes 8754 participants: 2212 people with a psychotic disorder, 1487 unaffected relatives of probands, and 5055 healthy controls. We investigated cognition [digit span (N = 3127), block design (N = 5491), and the Rey Auditory Verbal Learning Test (N = 3543)], electrophysiology [P300 amplitude and latency (N = 1102)], and neuroanatomy [lateral ventricular volume (N = 1721)]. We used linear regression to assess the interrelationships between endophenotypes.

RESULTS

The P300 amplitude and latency were not associated (regression coef. -0.06, 95% CI -0.12 to 0.01, p = 0.060), and P300 amplitude was positively associated with block design (coef. 0.19, 95% CI 0.10-0.28, p 0.38). All the cognitive endophenotypes were associated with each other in the expected directions (all p < 0.001). Lastly, the relationships between pairs of endophenotypes were consistent in all three participant groups, differing for some of the cognitive pairings only in the strengths of the relationships.

CONCLUSIONS

The P300 amplitude and latency are independent endophenotypes; the former indexing spatial visualisation and working memory, and the latter is hypothesised to index basic processing speed. Individuals with psychotic illnesses, their unaffected relatives, and healthy controls all show similar patterns of associations between endophenotypes, endorsing the theory of a continuum of psychosis liability across the population.

Widespread white matter microstructural differences in schizophrenia across 4322 individuals: results from the ENIGMA Schizophrenia DTI Working Group

The regional distribution of white matter (WM) abnormalities in schizophrenia remains poorly understood, and reported disease effects on the brain vary widely between studies. In an effort to identify commonalities across studies, we perform what we believe is the first ever large-scale coordinated study of WM microstructural differences in schizophrenia. Our analysis consisted of 2359 healthy controls and 1963 schizophrenia patients from 29 independent international studies; we harmonized the processing and statistical analyses of diffusion tensor imaging (DTI) data across sites and meta-analyzed effects across studies. Significant reductions in fractional anisotropy (FA) in schizophrenia patients were widespread, and detected in 20 of 25 regions of interest within a WM skeleton representing all major WM fasciculi. Effect sizes varied by region, peaking at (d=0.42) for the entire WM skeleton, driven more by peripheral areas as opposed to the core WM where regions of interest were defined. The anterior corona radiata (d=0.40) and corpus callosum (d=0.39), specifically its body (d=0.39) and genu (d=0.37), showed greatest effects. Significant decreases, to lesser degrees, were observed in almost all regions analyzed. Larger effect sizes were observed for FA than diffusivity measures; significantly higher mean and radial diffusivity was observed for schizophrenia patients compared with controls. No significant effects of age at onset of schizophrenia or medication dosage were detected. As the largest coordinated analysis of WM differences in a psychiatric disorder to date, the present study provides a robust profile of widespread WM abnormalities in schizophrenia patients worldwide. Interactive three-dimensional visualization of the results is available at www.enigma-viewer.org.

Neural correlates of exercise training in individuals with schizophrenia and in healthy individuals: A systematic review

A body of evidence has revealed positive effects of physical exercise on behavioral, cognitive and physical outcomes in patients with schizophrenia. Notably, the effect of exercise at the neural level may be particularly relevant as well as it is hypothesized that exercise may stimulate the brain in a way that might normalize neural alterations related to the disorder. The aim of the current systematic review was to provide an up to date overview of studies investigating the neural effects of exercise in individuals with a schizophrenia spectrum disorder and healthy individuals. The majority of included studies focused on hippocampal effects, reporting beneficial effects of exercise. In addition, in schizophrenia increased extrastriate body area (EBA) activation and increased white matter fiber integrity in tracts relevant to the disorder were found and in healthy individuals decreased connectivity of the dorsolateral prefrontal cortex (DLPFC) indicating greater cognitive efficiency was reported. Comparing individuals with a schizophrenia spectrum disorder and healthy individuals within a similar age range, most studies found similar effects on hippocampal volume and white matter tracts for both groups, although the effect in schizophrenia spectrum disorders may be attenuated which is in line with previous literature on brain plasticity. The current review indicates a lack of studies investigating neural correlates other than the hippocampus. Although those studies that did focus on other neural correlates revealed promising results, these have not been replicated in other studies and call for replication. Furthermore, future studies should expand their focus, by investigating neural mechanisms underlying positive effects of physical exercise on positive symptoms, negative symptoms and symptoms such as depression, social withdrawal and social cognition.

Brain morphology in antipsychotic-naïve schizophrenia: A study of multiple brain structures

Background

Although brain volume changes are found in schizophrenia, only a limited number of structural magnetic resonance imaging studies have exclusively examined antipsychotic-naïve patients.

Aims

To comprehensively investigate multiple brain structures in a single sample of patients who were antipsychotic-naïve.

Method

Twenty antipsychotic-naïve patients with first-episode schizophrenia and 20 healthy comparison subjects were included. Intracranial, total brain, frontal lobe, grey and white matter, cerebellar, hippocampal, parahippocampal, thalamic, caudate nucleus and lateral and third ventricular volumes were measured. Repeated-measures analyses of (co)variance were conducted with intracranial volume as covariate.

Results

Third ventricle volume enlargement was found in patients compared with the healthy subjects. No differences were found in other brain regions.

Conclusions

These findings suggest that some brain abnormalities are present in the early stages of schizophrenia. Moreover, it suggests that brain abnormalities reported in patients with chronic schizophrenia develop in a later stage of the disease and/or are medication induced.

[Residents in supported housing and factors related to moving towards independent living]

Few data are available on predictors for the transition of individuals with mental illness to more independent forms of housing.<br/> AIM: To analyse which variables predict the transition of individuals with severe mental illness from supported housing within the Dutch community housing programs (CHP) to more independent ways of living.<br/> METHOD: Data of 1569 participants were analysed using Cox regression analysis.<br/> RESULTS: Individuals with a personality disorder, current alcohol misuse or who received ambulant care prior to admission in CHP had the highest probability of moving to a more independent way of living. Individuals who received clinical care prior to admission in CHP, individuals with admission in Supported Housing, and individuals with a history of substance dependency had the highest probability of clinical relapse.<br/> CONCLUSION: The predictors found in this study can be used as a starting point both for hypotheses for additional aetiological research and for guidelines covering specific interventions.

Connectome organization is related to longitudinal changes in general functioning, symptoms and IQ in chronic schizophrenia

Emerging evidence suggests schizophrenia to involve widespread alterations in the macroscale wiring architecture of the human connectome. Recent findings of attenuated connectome alterations in unaffected siblings of schizophrenia patients suggest that altered connectome organization may relate to the vulnerability to develop the disorder, but whether it relates to progression of illness after disease onset is currently unknown. Here, we examined the interaction between connectome structure and longitudinal changes in general functioning, clinical symptoms and IQ in the 3years following MRI assessment in a group of chronically ill schizophrenia patients. Effects in patients were compared to associations between connectome organization and changes in subclinical symptoms and IQ in healthy controls and unaffected siblings of schizophrenia patients. Analyzing the patient sample revealed a relationship between structural connectivity-particularly among central 'brain hubs'-and progressive changes in general functioning (p=0.007), suggesting that more prominent impairments of hub connectivity may herald future functional decline. Our findings further indicate that affected local connectome organization relates to longitudinal increases in overall PANSS symptoms (p=0.013) and decreases in total IQ (p=0.003), independent of baseline symptoms and IQ. No significant associations were observed in controls and siblings, suggesting that the findings in patients represent effects of ongoing illness, as opposed to normal time-related changes. In all, our findings suggest connectome structure to have predictive value for the course of illness in schizophrenia.

GROUP 6 year outcome data in relation to antipsychotic medication

Objective

Genetic risk and outcome of psychoses (GROUP) is a 6 year longitudinal cohort study that focus on gene–environment vulnerability and resilience in patients with psychotic disorders, their unaffected family members and non-related controls. Its main aim is to elucidate etiological and pathogenetic factors that influence the onset and course of psychotic disorders. In this substudy, we will examine medication use over time, its relation with (the change in) metabolic syndrome status and effects on the brain.

Methods

A consortium of four university psychiatric centers and their affiliated mental health care institutions, conducted the GROUP study. At baseline, 1120 patients, 1057 siblings, 919 parents and 590 healthy controls were included. After inclusion, participants, except parents, were evaluated again after three and six years of follow-up. Extensive assessment of genetic factors, environmental factors, medication use, metabolic parameters and outcome were performed. Moreover, brain imaging was performed in a subset of participants, using a 1.5 Tesla MRI scanner.

Results

At baseline 65% of patients used atypical antipsychotics, 16% used conventional antipsychotics and 19% used clozapine. Siblings and controls used no antipsychotics. Forty-three percent of patients, 21.3% of siblings and 9.1% of controls used antidepressants; 43.9% of patients, 2.1% of siblings and none of the controls used a mood stabilizer. We are currently analyzing the medication data over time in relation to (change in) metabolic syndrome status and the effects on the brain.

Conclusion

GROUP is a longitudinal cohort study in patients with psychotic disorders, their healthy siblings and controls without psychosis. This naturalistic substudy examines medication use, its association with (change of) metabolic status and effects on the brain in subjects with (high risk of) psychosis.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Childhood abuse and neglect in relation to the presence and persistence of psychotic and depressive symptomatology

BACKGROUND

The association between childhood trauma and psychotic and depressive symptomatology is well established. However, less is known about the specificity and course of these symptoms in relation to childhood trauma.

METHOD

In a large sample (n = 2765) of patients with psychosis (n = 1119), their siblings (n = 1057) and controls (n = 589), multivariate (mixed-effects) regression analyses with multiple outcomes were performed to examine the association between childhood trauma and psychotic and depressive symptomatology over a 3-year period.

RESULTS

A dose-response relationship was found between childhood trauma and psychosis. Abuse was more strongly associated with positive symptoms than with negative symptoms whereas the strength of the associations between neglect and positive and negative symptoms was comparable. In patients, similar associations between childhood trauma and psychotic or depressive symptoms were found, and in siblings and controls, stronger associations were found between trauma and depressive symptomatology. Childhood trauma was not related to a differential course of symptoms over a 3-year time period.

CONCLUSIONS

In congruence with earlier work, our findings suggest that childhood trauma, and abuse in particular, is associated with (subthreshold) psychosis. However, childhood trauma does not seem to be associated with a differential course of symptoms, nor does it uniquely heighten the chance of developing (subthreshold) psychotic symptomatology. Our results indicate that trauma may instead contribute to a shared vulnerability for psychotic and depressive symptoms.

Factors contributing to the duration of untreated psychosis

BACKGROUND

Shortening the duration of untreated psychosis (DUP) - with the aim of improving the prognosis of psychotic disorders - requires an understanding of the causes of treatment delay. Current findings concerning several candidate risk factors of a longer DUP are inconsistent. Our aim was to identify factors contributing to DUP in a large sample that represents the treated prevalence of non-affective psychotic disorders.

METHOD

Patients with a non-affective psychotic disorder were recruited from mental health care institutes from 2004 to 2008. Of the 1120 patients enrolled, 852 could be included in the present analysis. Examined candidate factors were gender, educational level, migration status, premorbid adjustment and age at onset of the psychotic disorder. DUP was divided into five ordinal categories: less than one month, one month to three months, three months to six months, six months to twelve months and twelve months and over. An ordinal logistic regression analysis was used to identify the risk factors of a longer DUP.

RESULTS

Median DUP was less than one month (IQR 2). The factors migration status (p=0.028), age at onset of the psychotic disorder (p=0.003) and gender (p=0.034) were significantly associated with DUP in our analysis.

CONCLUSION

First generation immigrant patients, patients with an early onset of their psychotic disorder and male patients seem at risk of a longer DUP. These findings can assist in designing specific interventions to shorten treatment delay.

Insight change in psychosis: relationship with neurocognition, social cognition, clinical symptoms and phase of illness

OBJECTIVE

Impaired insight is an important and prevalent symptom of psychosis. It remains unclear whether cognitive disturbances hamper improvements in insight. We investigated the neurocognitive, social cognitive, and clinical correlates of changes in insight.

METHOD

One hundred and fifty-four patients with a psychotic disorder were assessed at baseline (T0 ) and after three years (T3 ) with the Birchwood Insight Scale, the Positive And Negative Syndrome Scale, measures of neurocognition and social cognition. Linear regression analyses were conducted to examine to what extend neurocognition, social cognition, clinical symptoms and phase of illness could uniquely predict insight change. Subsequently, changes in these factors were related to insight change.

RESULTS

Better neurocognitive performance and fewer clinical symptoms at baseline explained insight improvements. The additional effect of clinical symptoms over and above the contribution of neurocognition was significant. Together, these factors explained 10% of the variance. Social cognition and phase of illness could not predict insight change. Changes in clinical symptoms, but not changes in neurocognitive performance were associated with insight change.

CONCLUSION

Neurocognitive abilities may predict, in part, the development of insight in psychosis.

Schizophrenia genetic variants are not associated with intelligence

BACKGROUND

Schizophrenia is associated with lower pre-morbid intelligence (IQ) in addition to (pre-morbid) cognitive decline. Both schizophrenia and IQ are highly heritable traits. Therefore, we hypothesized that genetic variants associated with schizophrenia, including copy number variants (CNVs) and a polygenic schizophrenia (risk) score (PSS), may influence intelligence.

METHOD

IQ was estimated with the Wechsler Adult Intelligence Scale (WAIS). CNVs were determined from single nucleotide polymorphism (SNP) data using the QuantiSNP and PennCNV algorithms. For the PSS, odds ratios for genome-wide SNP data were calculated in a sample collected by the Psychiatric Genome-Wide Association Study (GWAS) Consortium (8690 schizophrenia patients and 11 831 controls). These were used to calculate individual PSSs in our independent sample of 350 schizophrenia patients and 322 healthy controls.

RESULTS

Although significantly more genes were disrupted by deletions in schizophrenia patients compared to controls (p = 0.009), there was no effect of CNV measures on IQ. The PSS was associated with disease status (R 2 = 0.055, p = 2.1 × 10-7) and with IQ in the entire sample (R 2 = 0.018, p = 0.0008) but the effect on IQ disappeared after correction for disease status.

CONCLUSIONS

Our data suggest that rare and common schizophrenia-associated variants do not explain the variation in IQ in healthy subjects or in schizophrenia patients. Thus, reductions in IQ in schizophrenia patients may be secondary to other processes related to schizophrenia risk.

Exercise therapy improves mental and physical health in schizophrenia: a randomised controlled trial

OBJECTIVE

The objective of this multicenter randomised clinical trial was to examine the effect of exercise versus occupational therapy on mental and physical health in schizophrenia patients.

METHOD

Sixty-three patients with schizophrenia were randomly assigned to 2 h of structured exercise (n = 31) or occupational therapy (n = 32) weekly for 6 months. Symptoms (Positive and Negative Syndrome Scale) and cardiovascular fitness levels (Wpeak and VO2peak ), as assessed with a cardiopulmonary exercise test, were the primary outcome measures. Secondary outcome measures were the Montgomery and Åsberg Depression Rating Scale, Camberwell Assessment of Needs, body mass index, body fat percentage, and metabolic syndrome (MetS).

RESULTS

Intention-to-treat analyses showed exercise therapy had a trend-level effect on depressive symptoms (P = 0.07) and a significant effect on cardiovascular fitness, measured by Wpeak (P < 0.01), compared with occupational therapy. Per protocol analyses showed that exercise therapy reduced symptoms of schizophrenia (P = 0.001), depression (P = 0.012), need of care (P = 0.050), and increased cardiovascular fitness (P < 0.001) compared with occupational therapy. No effect for MetS (factors) was found except a trend reduction in triglycerides (P = 0.08).

CONCLUSION

Exercise therapy, when performed once to twice a week, improved mental health and cardiovascular fitness and reduced need of care in patients with schizophrenia.

Age at onset of non-affective psychosis in relation to cannabis use, other drug use and gender

BACKGROUND

Cannabis use is associated with an earlier age at onset of psychotic illness. The aim of the present study was to examine whether this association is confounded by gender or other substance use in a large cohort of patients with a non-affective psychotic disorder.

METHOD

In 785 patients with a non-affective psychotic disorder, regression analysis was used to investigate the independent effects of gender, cannabis use and other drug use on age at onset of first psychosis.

RESULTS

Age at onset was 1.8 years earlier in cannabis users compared to non-users, controlling for gender and other possible confounders. Use of other drugs did not have an additional effect on age at onset when cannabis use was taken into account. In 63.5% of cannabis-using patients, age at most intense cannabis use preceded the age at onset of first psychosis. In males, the mean age at onset was 1.3 years lower than in females, controlling for cannabis use and other confounders.

CONCLUSIONS

Cannabis use and gender are independently associated with an earlier onset of psychotic illness. Our findings also suggest that cannabis use may precipitate psychosis. More research is needed to clarify the neurobiological factors that make people vulnerable to this precipitating effect of cannabis.

Brain volume reductions in medication-naive patients with schizophrenia in relation to intelligence quotient

BACKGROUND

Global brain abnormalities such as brain volume loss and grey- and white-matter deficits are consistently reported in first-episode schizophrenia patients and may already be detectable in the very early stages of the illness. Whether these changes are dependent on medication use or related to intelligence quotient (IQ) is still debated.

METHOD

Magnetic resonance imaging scans were obtained for 20 medication-naive patients with first-episode schizophrenia and 26 matched healthy subjects. Volume measures of total brain grey and white matter, third and lateral ventricles and cortical thickness/surface were obtained. Differences between the groups were investigated, taking into account the effect of intelligence.

RESULTS

Medication-naive patients showed statistically significant reductions in whole-brain volume and cerebral grey- and white-matter volume together with lateral ventricle enlargement compared to healthy subjects. IQ was significantly lower in patients compared to controls and was positively associated with brain and white-matter volume in the whole group. No significant differences in cortical thickness were found between the groups but medication-naive patients had a significantly smaller surface in the left superior temporal pole, Heschl's gyrus and insula compared to controls.

CONCLUSIONS

Our findings suggest that brain volume loss is present at illness onset, and can be explained by the reduced surface of the temporal and insular cortex. These abnormalities are not related to medication, but IQ.

Symptom dimensions are associated with progressive brain volume changes in schizophrenia

BACKGROUND

There is considerable variation in progressive brain volume changes in schizophrenia. Whether this is related to the clinical heterogeneity that characterizes the illness remains to be determined. This study examines the relationship between change in brain volume over time and individual variation in psychopathology, as measured by five continuous symptom dimensions (i.e. negative, positive, disorganization, mania and depression).

METHODS

Global brain volume measurements from 105 schizophrenia patients and 100 healthy comparison subjects, obtained at inclusion and 5-year follow-up, were used in this study. Symptom dimension scores were calculated by factor analysis of clinical symptoms. Using linear regression analyses and independent-samples t-tests, the relationship between symptom dimensions and progressive brain volume changes, corrected for age, gender and intracranial volume, was examined. Antipsychotic medication, outcome and IQ were investigated as potential confounders.

RESULTS

In patients, the disorganization dimension was associated with change in total brain (β=-0.295, p=0.003) and cerebellar (β=-0.349, p<0.001) volume. Furthermore, higher levels of disorganization were associated with lower IQ, irrespective of psychiatric status (i.e. patient or control). In healthy comparison subjects, disorganization score was not associated with progressive brain volume changes.

CONCLUSION

Heterogeneity in progressive brain volume changes in schizophrenia is particularly associated with variation in disorganization. Schizophrenia patients with high levels of disorganization exhibit more progressive decrease of global brain volumes and have lower total IQ. We propose that these patients form a phenotypically and biologically homogenous subgroup that may be useful for etiological (e.g., genetic) studies.

The course of brain abnormalities in schizophrenia: can we slow the progression?

There is convincing evidence that schizophrenia is characterized by progressive brain volume changes during the course of the illness. In a large longitudinal study it was shown that different age-related trajectories of brain tissue loss are present in patients compared with healthy subjects, suggesting that brain maturation that occurs in the third and fourth decade of life is abnormal in schizophrenia. Studies show that medication intake is an important confounding factor when interpreting brain volume (change) abnormalities. Atypical antipsychotics have been found to be related to smaller decreases in tissue loss. Moreover, independent of antipsychotic medication intake, the brain volume abnormalities appear associated to the outcome of the illness. Before being able to intervene with therapies and prevent the brain from shrinking, one has to understand the underlying mechanism of the progressive changes in the brains of schizophrenia patients.

Movement disorders are associated with schizotypy in unaffected siblings of patients with non-affective psychosis

BACKGROUND

Movement disorders and schizotypy are both prevalent in unaffected siblings of patients with schizophrenia and both are associated with the risk of developing psychosis or schizophrenia. However, to date there has been no research into the association between these two vulnerability factors in persons with an increased genetic risk profile. We hypothesized that unaffected siblings of patients with non-affective psychosis have more movement disorders and schizotypy than healthy controls and that these co-occur.

METHOD

In a cross-sectional design we assessed the prevalence and inter-relationship of movement disorders and schizotypy in 115 unaffected siblings (mean age 27 years, 44% males) and 100 healthy controls (mean age 26 years, 51% males). Movement disorders were measured with the Abnormal Involuntary Movement Scale (AIMS), the Unified Parkinson Disease Rating Scale (UPDRS), the Barnes Akathisia Rating Scale (BARS), and one separate item for dystonia. Schizotypy was assessed with the Structured Interview for Schizotypy--Revised (SIS-R).

RESULTS

There were significant differences in the prevalence of movement disorders in unaffected siblings versus healthy controls (10% v. 1%, p<0.01) but not in the prevalence of schizotypy. Unaffected siblings with a movement disorder displayed significantly more positive and total schizotypy (p=0.02 and 0.03 respectively) than those without. In addition, dyskinesia correlated with positive schizotypy (r=0.51, p=0.02).

CONCLUSIONS

The association between movement disorders (dyskinesia in particular) with positive and total schizotypy in unaffected siblings suggests that certain vulnerability factors for psychosis or schizophrenia cluster in a subgroup of subjects with an increased genetic risk of developing the disease.

Cigarette smoking and progressive brain volume loss in schizophrenia

It is unknown whether the reported brain loss in schizophrenia can be attributed to the effects of tobacco smoking. 96 Patients (54 smokers/42 non-smokers) and 113 control subjects (35/78) were included in a 5-year longitudinal MRI study. Despite the higher prevalence of smoking behavior and the higher number of cigarettes consumed per day in the patients, cigarette smoking did not explain the excessive cerebral (gray matter) volume decreases in the patients. Moreover, smoking was not associated with brain volume change over time in the healthy subjects. However, extremely heavy smoking may contribute to excessive gray matter volume loss in schizophrenia.

First contact incidence of psychotic disorders among native Dutch and Moroccan immigrants in the Netherlands: influence of diagnostic bias

BACKGROUND

Several studies have reported increased incidence rates of psychotic disorders among immigrant groups. Surprisingly, the cross-cultural validity of the diagnostic instruments that were used was never tested.

AIMS

To examine whether the incidence rates of psychotic disorders including schizophrenia among Moroccan immigrants to the Netherlands remain increased when a cultural sensitive diagnostic interview is used.

METHOD

We compared first contact incidence with a standard and a cultural sensitive version of a diagnostic interview.

RESULTS

Age and gender adjusted relative risk for psychotic disorders and schizophrenia among Moroccans compared to native Dutch was 7.9 (95% CI 4.7-13.5) and 7.8 (95% CI 4.0-15.2) respectively based on the standard diagnostic interview and 4.2 (95% CI 2.3-7.9) and 1.5 (0.5-4.3) respectively based on the cultural sensitive version the diagnostic interview.

CONCLUSION

First contact incidence of schizophrenia among Moroccans was no longer significantly higher than among ethnic Dutch people when a cultural sensitive diagnostic procedure was applied.

[Routine Outcome Monitoring for patients with severe mental illness: a consensus document]

BACKGROUND

Routine outcome monitoring (ROM) means the assessment of the patient's condition on a routine basis using instruments. So far there is no consensus about which instruments should be used for ROM with severely mentally ill patients (ROM-SMI).

AIM

To reach a consensus about instruments for ROM-SMI in the Netherlands and Belgium and to create possibilities for comparison of ROM data.

METHOD

This article discusses the consensus document of the National Remission Working Group for ROM in patients with smi and covers the following topics: reasons for ROM-SMI, domains for ROM-SMI and appropriate instruments, logistics and analyses of the data.

RESULTS

Patients with SMI have problems in several domains. These can be assessed by collecting information about psychiatric symptoms, addiction, somatic problems, general functioning, needs, quality of life and care satisfaction. Potential instruments for ROM-SMI are short, valid, reliable and assess several domains, taking the patient's perspective into account, and have been used in national and international research. The working group advises institutions to choose from a limited set of instruments. After the scores have been aggregated and standardised, comparisons can be drawn. ROM-SMI data can be interpreted more meaningfully, if outcome data are supplemented with data regarding patient characteristics and the treatment interventions already applied.

CONCLUSION

It should be possible to reach a consensus about instruments for ROM-SMI and the way in which they should be used. The use of identical instruments will lead to improvements in mental health care and create possibilities for comparison (benchmarking) and research.

Psychosis and brain volume changes during the first five years of schizophrenia

The underlying mechanisms explaining brain volume changes in schizophrenia are not yet understood, but psychosis might be related to these changes. Forty-eight patients with first-episode schizophrenia underwent Magnetic Resonance Imaging brain scanning at inclusion and after five years. An association was found between longer duration of psychosis, larger gray matter volume decrease and larger ventricular volume increase. These findings strongly suggest that psychosis contributes to brain volume reductions found in schizophrenia.

CNTNAP2 gene dosage variation is associated with schizophrenia and epilepsy

A homozygous mutation of the CNTNAP2 gene has been associated with a syndrome of focal epilepsy, mental retardation, language regression and other neuropsychiatric problems in children of the Old Order Amish community. Here we report genomic rearrangements resulting in haploinsufficiency of the CNTNAP2 gene in association with epilepsy and schizophrenia. Genomic deletions of varying sizes affecting the CNTNAP2 gene were identified in three non-related Caucasian patients. In contrast, we did not observe any dosage variation for this gene in 512 healthy controls. Moreover, this genomic region has not been identified as showing large-scale copy number variation. Our data thus confirm an association of CNTNAP2 to epilepsy outside the Old Order Amish population and suggest that dosage alteration of this gene may lead to a complex phenotype of schizophrenia, epilepsy and cognitive impairment.

[Prevention and treatment of somatic complications arising from the use of antipsychotics]

BACKGROUND

Antipsychotics are effective drugs that are prescribed frequently for a large group of patients. However, they also have many side-effects which can lead ultimately to serious somatic complications. These complications fall into various categories: metabolic, cardiovascular, neurobiological, haematological, gastro-intestinal and urogenital.

AIM

To make an inventory of the side-effects and advise on ways of monitoring and preventing them. method The multidisciplinary working group on somatic complications arising from the use of antipsychotics (Werkgroep Somatische Complicaties) has collected literature on the subject and has discussed it at a number of consensus meetings. results The most frequent somatic complications are described on the basis of specific risk profiles and advice is given on how to identify these complications and on how to treat them when necessary. It is essential to monitor, systematically and regularly, somatic complications arising from the use of antipsychotics; furthermore, polypharmacy should be avoided. The person ultimately responsible for this is the doctor who has prescribed the antipsychotics. In addition, it is important to draw patients' attention to the general rules for a healthy lifestyle: no smoking, a balanced diet and adequate exercise.

CONCLUSION

It is very important that somatic complications should be monitored carefully and accurately. So far, the Netherlands has no official guidelines on ways to identify and treat somatic complications.

Brain volume changes in the first year of illness and 5-year outcome of schizophrenia

Progressive brain volume changes have been reported in first-episode schizophrenia, but their relationship to the disease process or to other factors remains unclear. We examined such changes in the first year of illness, and related them to 5-year outcome. Progressive brain volume changes, in particular of grey matter, during the first year of illness were found to be significantly associated with clinical and functional outcome 5 years after the first episode. These findings suggest that early dynamic brain volume changes are related to the disease process and predict the longer-term outcome of schizophrenia.

Focal white matter density changes in schizophrenia: reduced inter-hemispheric connectivity

Gray matter changes have been demonstrated in several regions in schizophrenia. Particularly, the frontal and temporal cortices and amygdala-hippocampal region have been found decreased in volume and density in magnetic resonance imaging (MRI) studies. These abnormalities may reflect an aberrant neuronal network in schizophrenia, suggesting that white matter fibers connecting these regions may also be affected. However, it is unclear if particular white matter areas are (progressively) affected in schizophrenia and if these are related to the gray matter changes. Focal white matter changes in schizophrenia were studied in whole brain magnetic resonance images acquired from 159 patients with schizophrenia or schizophreniform disorder and 158 healthy comparison subjects using voxel-based morphometry. White matter density changes in the patients with schizophrenia were correlated to gray matter density changes and to illness severity. In the patients with schizophrenia, significant decreases in white matter density were found in the genu and truncus of the corpus callosum in the left and right hemisphere, in the right anterior internal capsule and in the right anterior commissure. No interactions between diagnosis and age were found. Increased illness severity was correlated with low density of the corpus callosum and anterior commissure. Decreased corpus callosum density correlated with decreased density of thalamus, lateral inferior frontal and insular gray matter in patients and controls and with decreased density of medial orbitofrontal and superior temporal gyri in patients. Decreased internal capsule and anterior commissure density correlated with increased caudate, and globus pallidus density in patients and controls. These findings suggest aberrant inter-hemispheric connectivity of anterior cortical and sub-cortical brain regions in schizophrenia, reflecting decreased hemispheric specialisation in schizophrenia.

Excessive recruitment of neural systems subserving logical reasoning in schizophrenia

Schizophrenic patients generally perform poorly on tasks that address executive functions. According to several imaging studies, the dorsolateral prefrontal cortex is hypoactive in schizophrenic patients during these tasks. It is not, however, clear whether this finding is associated more with impaired performance than with the illness itself, as performance has not been taken into account. We examined brain activity associated with executive function in schizophrenia using an experimental fMRI design that reveals performance effects, enabling correction for performance differences between groups. As this approach has not been reported before, and because brain function can be affected by medication, the effect of antipsychotic medication was also investigated. A task was used that requires logical reasoning, alongside a closely matched control task. Performance was accounted for by including individual responses in fMRI image analyses, as well as in group-wise analysis. Effects of medication were addressed by comparing medication-naïve patients and patients on atypical antipsychotic medication with healthy controls in two separate experiments. Imaging data were analysed with a novel, performance-driven method, but also with a method that is similar to that used in earlier studies, which reported hypofrontality. A modest reduction in performance was found in both patient groups. Brain activity associated with logical reasoning was correlated positively with performance in all groups. In patients on medication, activity did not differ from that in controls after correcting for difference in performance. In contrast, performance-corrected activity was significantly elevated in medication-naïve patients. This study indicates that schizophrenia may be associated with excessive recruitment of brain systems during logical reasoning. Considering the fact that performance was reduced in the patients, we argue that the efficiency of neural communication may be affected by the illness. It appears that in patients on atypical antipsychotic medication, this neural inefficiency is normalized. The study shows that performance is an important factor in the interpretation of differences between schizophrenic patients and controls. The reported association between performance and brain activity is relevant to clinical imaging studies in general.